I'm using opencart 2.0.3.1 at www.deccan-dental.com and i'm also using wordpress site on the same server with a different directory @ www.deccan-dental.com/newsite.
My problem is i'm getting 500 internal server error after installing a plugin in wordpress site and it is giving me the notice of PHP version update. I would like to ask you that If I update the PHP version from 5.3+ to latest then is there any chance to get my opencart site crashed? Please some one help answering this question. Thanks in advance

I contacted all the extension developers and they told that their extensions work as long the Opencart works on the desired PHP version and some one also told that Opencart is safe upto PHP 7.0 and will not compatible with 7.2.

Can anyone suggest me how easily and safely update my PHP version to the latest without being damaged to my website

The most generated errors being found on Opencart forum originates from contributed programming. The increased post counters are caused by redundancies of the same solutions that were already provided prior.

How do you deal with mcrypt being deprecated? I know it has been replaced in the latest version with openssl_encrypt, but I have a store running 2.2.0.0 that has been moved to PHP 7.2.1 and it's having issues with this.

system/library/encryption.php did had changes over the years without the need of mcrypt.

The most generated errors being found on Opencart forum originates from contributed programming. The increased post counters are caused by redundancies of the same solutions that were already provided prior.

Here's a drop in replacement for system/library/encryption.php that will work on OC1.5.6.4 and PHP7.2. Unlike the current version used in OC3, this will not produce the empty iv warning "Warning: openssl_encrypt(): Using an empty Initialization Vector (iv) is potentially insecure and not recommended"

@billynoah:
Well, thanks a million for this piece of Code, it solved a potentially fundamental Problem,
since my 1.5.6.x was not able to pass the PHP 7.0.xx Mark, as it comes. But now, everything
changed, and the future looks bright again, encouraging me to a great extend!
It's like getting a late Christmas Gift !!!
Ernie
---

Glad I could help Ernie. I originally submitted a variation of this as a rewrite for OC2+ due to the empty IV issue that throws a warning on current PHP versions. The rewritten function uses all modern openssl() functions and there is a pull request in here (https://github.com/opencart/opencart/pull/6326) to have it integrated into the main repository. If you feel it's an improvement, please drop a comment there so we can get this merged.

The most generated errors being found on Opencart forum originates from contributed programming. The increased post counters are caused by redundancies of the same solutions that were already provided prior.

I installed the script shown above for OC 1.5.6.4 operating on PHP7.2 and still no luck - any suggestions? I also have to do it for OC2.3.0 so will use the appropriate script for that as well.

Thanks for any suggestions

At this point, I really wouldn't suggest to v1.5x releases for the latest release of PHP … I would rather suggest at least the use of v2.3.0.2 release of OC. Otherwise, OC v3.x releases.

The most generated errors being found on Opencart forum originates from contributed programming. The increased post counters are caused by redundancies of the same solutions that were already provided prior.